[Frontiers in Bioscience 3, c27-33, May 1, 1998] |
LURIE’S TUBERCLE-COUNT METHOD TO TEST TB VACCINE EFFICACY IN RABBITS
Departments of Environmental Health Sciences, Molecular Microbiology and Immunology, and Epidemiology, School of Hygiene and Public Health; and the Department of Pathology, School of Medicine, The Johns Hopkins University, Baltimore, Maryland 21205
Received 3/9/98 Accepted 3/14/98
6. HOW VACCINES PREVENT GROSSLY VISIBLE TB LESIONS
No tuberculosis vaccine will appreciably increase the power of the alveolar macrophages (AM) to destroy tubercle bacilli in an immunologically-specific manner. AM are not immunocytes and therefore do not recognize specific antigens. However, AM can recognize certain bacterial components in a broadly specific manner, because all macrophages have some innate resistance to microorganisms (15,16). In contrast, various clones of lymphocytes have specific receptors for various antigens of the tubercle bacillus, and these lymphocyte clones expand when presented with antigens in the vaccine. In the vaccinated host, the increased numbers of antigen-specific lymphocytes cause a more rapid development of both tissue-damaging DTH (producing caseous necrosis) and CMI (producing macrophage activation). Therefore, bacillary multiplication is inhibited sooner, and fewer lesions progress to grossly visible size.